Communication systems have been developed to support higher data rate to meet the need for steadily increasing wireless data traffic. For example, fourth generation wireless communication systems has sought to develop technologies toward improving spectral efficiency to increase data rate.
Since such technologies are not enough to meet the need for soaring wireless data traffic, communication systems have been developed to secure a new frequency band. For example, since a wide frequency band is hardly secured below 10 GHz, communication at higher frequencies than 10 GHz is drawing attention as a future communication technology. However, the higher the transmission frequency for wireless communication, the shorter the propagation range, thus causing reduction of service coverage.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.